Ms. Chrapaty is director of technology at the National Basketball Association. She oversees everything from the phone system to the points posted on the scoreboard.

That's unusual. Whether in the NBA or IBM, men are often at the helm when it comes to technology. That includes everything from computer programmers to Internet site designers.

And new evidence suggests that women are actually losing representation in computer science and engineering fields, raising concerns that women - who make up half the country's work force - will be left out of a key job market of the future.

"It's still a boys' club, both in academia and in the [information technology] departments of companies," says Renee Colwell, president of the New York chapter of the Association for Women in Computing.

"I'm a woman battling on a daily basis in a man's field," contends the quick-witted Chrapaty.

"I've gone into rooms where people ask me to get them a cup of coffee. I take it as a joke," she says, describing how she gets the coffee and then sits down at the head seat. "Then they say, 'So, you're Debra,' " realizing that she's their boss.

What's at stake for industry is remaining competitive. The high-tech industry needs more skilled workers. What's at stake for women is nothing less than their future earning power.

US Labor Department projections show the computer field generating about 1 in 6 new US jobs by 2005. Yet the proportion of women in computing fields has dropped significantly since 1990.

But if women in the computing field are discouraged by their declining representation, they also see reason for hope. The high-tech industry is still evolving, and the "old boys' network" is not very entrenched.

"Here's a chance where [women] can impact the industry and be pioneers," says Aliza Sherman, president of Cybergrrl Inc., a two-year-old Internet site for women and girls (address: www.cybergrrl.com). As a result, she says, women can rise quickly, particularly in start-up firms.

If it sounds as if Ms. Sherman has fine-tuned her sales pitch, she has. She and Chrapaty joined a dozen exhibitors at a recent high-tech science fair here in New York - the nation's first exclusively for girls.

Part of her intent was to pique an interest in math and science among the 80-plus elementary and high school students who attended. She also hopes to serve as a role model for girls interested in computer science.

"If you asked me for a list of role models that helped me get into technology, they'd all be men," Sherman says.

EXPERTS cite a number of other reasons for women's declining presence in computing fields.

* A consolidation in the high-tech industry in the 1980s hit jobs held by women more than those held by men.

* Boys learn about computers early through video games, which are created largely for them, not for girls. "We're not validating girls' use of technology in society," says Janese Swanson, founder of Girl Tech, a California-company that is rolling out a line of computer products for girls.

* Fewer young women choose math and science in schools. Girls face a stereotype that degrades their talent for equations and scientific analysis. By high school, studies show, girls have often lost interest, and even worse, confidence, in such subjects.

As a result, the number of women earning technical degrees is dropping.

By 1994, only 28 percent of computer science degrees were earned by women, compared with 37 percent 10 years earlier, according to the US Department of Education.

But more women today are breaking into such fields using their own know-how.

"Women tend to come into the field by the back door," says Ms. Colwell. "It's easier, less competitive, and less intimidating." Colwell, for example, has a psychology degree, but she taught herself to program a computer 10 years ago. Now she's an independent computer consultant, designing computer systems for businesses.

The shortage of women in computing is well-known to corporate America. At IBM Corp., only 28.7 percent of US employees in technical positions are women - about the same proportion as in IBM management positions.

Many big computer companies say they are actively trying to bring more women into the field through scholarships and recruiting at women's colleges.

As the girls at the science fair here adeptly rebuilt toasters, surfed the Internet, and learned about the principles of fiber optics, they showed none of the self-doubt that some experts say limits their exposure to computing.

One six-year-old, checking out the NBA's Internet site asked matter-of-factly: "Why are there so many men on the screen?"

Tips From Women in Technology

'Don't shy away from tech courses. Have no fear. Don't be intimidated if you're the only girl there.'

- Aliza Sherman of Cybergrrl Inc., a Web site for women and girls.

'Find a mentor and ... opportunities to do hands-on research. It fosters a feeling of confidence, of "I can do this." '